social behaviour

• social hierarchy

  individuals organised into rank. higher (dominants) lower (subordinates) eg. grey wolf, hens, chimpanzees
• benefit of social hierarchy

  ritualistic displays REDUCE aggression and injury within the group

  appeasement behaviour REDUCES conflict

  subordinate animals benefit from protection and food provided by the group

  dominant animals access mates passing on favourable genes
• dominant behaviour

  raised hackles, showing teeth
• submissive behaviour

  avoiding eye contact, getting low to the ground, exposing vulnerable body parts
• cooperative hunting

  where animals hunt as a group eg. killer whales, lions, wild dogs
• benefits of cooperative hunting

  kill is shared among all members

  subordinates gain more food than by hunting alone

  less energy is used per individual

  larger prey can be killed

  increased hunting success rate
• social defence

  when animals defend together or raise an alarm eg. prairie dogs, geese, baboons
• benefits of social defence

  increases chance of survival as some individuals can watch for predators whilst others can forage for food

  groups adopt specialised formations when under attack, protecting their young
• altruistic behaviour

  harms the donor but benefits the recipient
• reciprocal altruism

  when the roles of the donor and recipient reverse, one animal gives help to another with the expectation that the favour will be returned
• kin selection

  leads to the extreme altruism of the workers of social insects

  occurs between related individuals

  individuals reduce their net lifetime production of offspring to help their relatives reproduce

  donor benefits as they have an increased chance of survival of shared genes in the recipients offspring